JPH0230414A - Drill - Google Patents

Abstract

PURPOSE:To make easy of discharge on cutting chip by forming cutting chip discharging channels in shallow and in nearly L letter shape in sectional form, and pressing a cutting chip on a flat plate part with a wall on rear side in rotational direction, while preventing the cutting chip from curing on making the cutting chip abut on a front side wall at a side end part. CONSTITUTION:A cutting chip discharging channel 3 is made to be in nearly L letter shape in cross sessional form, and an angle between a front side wall 31 in rotational direction and a rear side wall 32 is made in about 90 deg.. Together with formation of a projection 33 on the front side wall 31, a wall 35 is formed at a position retreated from the wall 31 on outer peripheral side than the projection. A generated cutting chip is pushed up as being pressed to the wall 32 at a flat plate part 40, and the same is moved into a portion widened on account of the wall 35 as being pressed to the wall 31 at a side part for being prevented from curling, thereby discharge is performed smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a drill suitable for drilling deep holes in which a chip discharge groove is formed in a spiral or linear shape.

[Prior art] - In general, a drill has a spiral chip ejection groove formed on its shank, and the chips are curled through this chip ejection groove.
The chip is discharged in a shape called a conical spiral, and the chip rotates with the rotation of the drill and winds up around the surrounding parts of the equipment. It has become an obstacle. Attempts have also been made to form short, fragmented chips in which the chips are not continuous. Furthermore, in order to smoothly discharge the chips, the conventional drill has a large opening for curled chips to easily pass through.

(Problems to be Solved by the Invention) As mentioned above, when the chips are curled and discharged, there is a problem in that it takes time and effort to remove them.
Particularly when machining deep holes, there is a problem that the chips are not released well, and the chips become clogged when they are fully discharged, making it impossible to perform drilling. In order to improve discharge performance, cut 1i% JJ
If the I groove is formed to be large, the torsional rigidity of the shank decreases, causing the problem that efficient hole machining cannot be performed.

When drilling deep holes, it is necessary to supply oil to the cutting part, but when oil is supplied from the outside through a vortex where chips υ1 emerge, the curled chips become moon-shaped and '+7' is an upper R? 1. It is difficult to scoop up the mail supplied to the cutting surface in order to avoid oil reaching the cutting part. As a countermeasure for this, conventionally, when using a drill with a right-handed helix, a hole is formed in the axial direction at the link (7) and then twisted to form an oil supply port. It was necessary to cover the complex machining.

This invention was made in order to eliminate and overcome these conventional drawbacks, and by forming the swarf in a shallow, hollow-shape, the rigidity of the drill is increased and the swarf is kept in a continuous state. By preventing curling and ejecting chips, this method allows chips to be smoothly ejected from d5 to 16 during deep hole machining without increasing the groove depth. The object of the present invention is to provide a drill in which the discharged chips are naturally broken when they come out of the machined hole or when they are removed from the drill. .

[Means for deciding issues]

The first gist of the invention is that the chip exit groove is formed in a spiral or straight line on the shank, and a pair of cutting edges are provided at the tip of the shank in a continuous manner from the center of rotation to the outer periphery. In the drill formed by the cutting edge, the flat root of the chip formed by the cutting edge on the outer circumferential side comes into contact with the rear wall in the rotating direction of the drill to which the flat root part of the chip is crimped, so that the chip curls. Each chip 'kAl outflow vortex is formed by the wall on the front side in the rotational direction, which prevents the cutting.

The second gist of the invention is that when the chip discharge groove is formed in the shank in a spiral or linear shape, a pair of cutting edges are provided at the tip of the shank continuously from the center of rotation to the outer periphery. In the drill, each chip evacuation groove has a cross-sectional shape of approximately (-), and the angle between the front wall and the rear wall in the direction of rotation of the chip ejection groove is 700° to 1.
This is set within the range of 200.

The depth of the above chip discharge groove is 0°25 to 0 of the diameter of the drill.
．． It is preferable to set it within a range of 10 times. Again”-
The chip discharge groove may be formed by retracting the front wall so that the outer peripheral side of the groove is widened toward the front in the rotational direction.

[Effect]

The structure described in - () is a flat plate in which the chips are prevented from being curled by the wall of chips υ1, and the chips in the center undergo plastic deformation that is stretched by the outer chips. The chips are continuously ejected from the machined hole, and are broken by centrifugal force and being bent outward at the terminal end (ten end) of the ejection groove.In the ejection groove, the chips are continuously ejected. Because of this, it can be smoothly discharged without getting clogged in the whirlpool even when drilling deep holes.

Furthermore, to prevent the chips from curling, apply oil to the chips 77+
It is also easily possible to supply the cutting portion from the fH groove.

(Example) In FIGS. 1 to 3, a chip discharge groove 3 is formed in a spiral shape in the shank 10 of the drill, and the top of the shank 10 is formed in a conical shape, and the rotation center O at the tip is located at the starting point. A pair of cutting edges 2 are formed point-symmetrically. This cutting edge 2 consists of a cutting edge 21, which is sharpened on the beveled part, and a cutting edge 22, which is on the outer circumferential side. It is formed into a mountain shape with the connection point with the cutting blade 22 as the apex. This cutting blade 21
．． 22 may be formed into a curve curved either forward or backward in the rotational direction.

The top surface of the shank 10 is composed of a tightened surface 13 of the cutting blade 2, and a land portion 20 formed of an inclined surface rearward in the direction of rotation.

The cross-sectional shape of each chip discharge groove 3 is approximately 1-shaped, and the M angle between the front wall 31 and the rear wall 32 in the rotational direction of the chip discharge groove 3 is set to 90Q. ing. This angle may be set within the range of 70' to 1200°, preferably within the range of 85° to 100°. If the angle is too large, the effect of preventing the chips from curling due to pressure bonding to one side of the chips, which will be described later, will not be achieved.
Furthermore, if J: is set to a small angle, machining of fM becomes difficult.

Further, the chip discharge groove 3 is formed by receding (shaving off) the front wall 31 so that the outer peripheral side thereof is expanded forward in the rotational direction. That is, a protrusion 33 is formed on the front wall 31, and a wall 31 is formed on the outer peripheral side of the front side.
A wall 35 is formed at a more retreated position. Also wall 3
Instead of forming the groove width 5, a slanted wall 39 may be formed, in which the width of the groove increases at the outer periphery. This protrusion 33 extends continuously along approximately the center of the chip discharge groove 3 (not shown in FIG. 1).

It is preferable that the groove depth A of the chips II and 3 is set within a range of 0.25 to 0.40 times the diameter of the drill 10. If the groove depth is smaller than this, it will be difficult to discharge chips, and if it is deeper than this, the rigidity of the shank 10 will be weakened.

The drawing shows an example in which the groove depth A is set to 0.25@ which is the diameter of the drill. In addition, the dimension B of the enlarged outer peripheral part of the chip 1 no. 1 exit groove 3 is about 0.15D, C is 0, IDPi1
You can set it once.

FIG. 4 shows another embodiment of the present invention, in which the chip discharge groove 3! The difference is that the wall 31 is formed from walls 31 and 32 that are orthogonal to each other, or that the wall 31 is not formed with a protrusion 33 and that the wall 31 extends to the outer periphery.

The walls 31 and 32 forming the chip discharge groove 3 are each formed in a straight line with a cross-sectional shape of J5, and the hearing angle between them is set to 90°.
Various modifications are possible as shown in the figure.

41, that is, in FIG. 5, the wall 6 on the front side in the direction of rotation of the drill
1 and the rear wall 62 are formed with a hearing angle of 120'', and each wall 61d3 and 62 falling in the cross-sectional shape is formed in a straight line. FIG. Walls 63 and 64 are formed that are curved inwardly (on the side of the chip discharge groove 3), and the substantial hearing angle θ at the base of both (near the intersection) is formed small. wall 6
1, 62 are replaced by outwardly curved walls 65, 66.

Although not shown, the walls 61 and 64, the walls 6
1st wall 66, wall 63 and wall 62, wall 63 and wall 66, wall 65
The combination of the walls 62, 65, and 64 may have a groove shape.

Further, in FIG. 8, the chip discharge groove 3 is formed in a U-shape with a narrow groove width, the wall 72 at the rear in the direction of rotation is formed in a straight line, and the wall at the front in the direction of rotation is curved near the base end. : A wall 71 is formed, and a straight wall 73 is formed on the outside thereof. In this case, the thickness of the chip discharge groove 3 and the curvature r of the wall 71 are such that chips 4 are generated without any problem, as shown in FIG. 8, for example, 1/10 of the diameter of the drill.
It is sufficient to set the degree or its value to a larger value.

In FIG. 9, instead of walls 72 and 73, walls 74 and 75 are formed that are curved inward (toward the chip discharge groove 3 side).

In FIG. 10, instead of straight walls 72 and 73, outwardly curved walls 76 and 77 are formed.

In this case as well, the walls 72 and 75, the walls 72 and 77, the walls 73 and wall A4, the walls 73 and walls 76, and the walls 75 and 7
6. A groove shape may be formed by a combination of walls 77 and 77.

Hole drilling is performed using the drill with the above configuration.
Chips 4 as shown in FIG. 11 are generated. That is,
The chips 4 consist of a small curl portion 41 generated near the center of the cutting edge 2 and a flat plate portion 40 generated on the outer peripheral side thereof, and extend integrally from one side of the flat plate portion 40. Curled portions 41 are formed intermittently in the length direction of the flat plate portion 40, and cracks 44 are formed on the negative side portions.

The chips 4 having such a shape are generated in the flat plate portion 40 of the chips that are extruded into the chip discharge groove 3 after being cut into the outer circumferential portion (the cutting blade 22) of the cutting blade 2 by a J-shape, as shown in FIG. One side of the wall 31 is crimped to the base of the wall 31, and its surface is crimped to the wall 32, preventing it from curling (in addition to plastic deformation during cutting, chips on the outer periphery It undergoes plastic deformation (stretched) and becomes a flat band-like body with cracks 44 on the above-mentioned side and is pushed up in the chip IJI outlet groove 3. The chip then ascends along the loose spiral shape of the chip discharge groove 3, emerges from the machined hole, and is broken off at the crack 44 by centrifugal force. In addition, if the drilled hole is deep, the chips 4 are bent outward at the curved part 33 at the upper end, as shown in Figure 1, and as a result, in addition to cracking, the chips 4 undergo large plastic deformation and become brittle. is broken into pieces.

In addition, in the structure shown in FIGS. 1 to 3, when the flat plate part of the chips 4 is generated, it is pushed up in the discharge groove 3 while being pressed against the scoop 32a, and the - side part is pressed against the wall. However, as shown in Fig. 3, the outer part of the cut 1 and 4 eventually moves to the part widened by the wall 35 due to interference from the inner wall of the machined hole, thereby making it easier to eject the chips 4. It will make it go smoothly. By forming the wall 335 in this way, the wall 31 serves to press one side of the flat plate part 40 to prevent the chips from curling, and the discharge groove 3 in the outer part thereof is prevented from curling. Since the expanded portion makes it easier for chips to pass through, the effect of smoothly discharging chips 4 is effectively exhibited, especially when drilling deep holes.

In addition, in the configuration shown in FIG. 5, the chips 4 are removed from the flat plate portion 4.
Ob
In the configuration shown in FIG. Due to the contact, the chips 4 are prevented from curling in the chip discharge groove 3 and are discharged.

The configurations shown in FIGS. 6, 7, 9, and 10 achieve the same effects as those shown in FIGS. 5a3 and 8, respectively.

In addition, in the above structure, the chips 4 are extruded in a flat shape without being curled during the discharge process, so the depth of the chip discharge groove 3 does not need to be increased. The core thickness of the shank 10 can be increased, thereby increasing the rigidity of the shank 17, thereby preventing core run-out during drill machining.

In addition, in the former Nasei, since the discharged chips do not scoop up the oil supplied into the chip discharge groove, oil can be supplied from the outside through the chip discharge groove.
Therefore, there is an advantage that it is not necessary to form an A-il supply [1] in the drill.

Further, in the above embodiment, only an example in which the chip discharge groove +#3 is formed in a spiral shape on the shank is shown, but the chip discharge groove is not limited to this, and the chip discharge groove may be formed in a linear shape in the shank.

〔Effect of the invention〕

As explained above, according to the present invention, chips are prevented from being curled by the walls of the chip discharge groove, undergo plastic deformation (j), are made into a flat plate shape and are continuously discharged, and are
When the hole protrudes a certain distance, it is broken by centrifugation), and in the case of a deep hole, it is broken by being bent outward at the terminal end (upper end) of the discharge groove. Since chips are continuous in the extraction groove, they do not become clogged in the groove even during deep hole drilling and are smoothly discharged.

J: /j Since the groove depth of the chip discharge groove is shallow, the rigidity of the shank is improved, and therefore deep hole machining can be performed with high efficiency and precision, and high feed machining is also easy.

A further advantage is that oil can be supplied from the outside through the chip discharge groove, and therefore there is no need to form an A oil supply port in the trough 1/I.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, a partially cutaway side view of a J drill, Fig. 2 a bottom view thereof, Fig. 3 a sectional view taken along the line ■-■ in Fig. 1, and Figs. 4 to 10. 3 is a view corresponding to FIG. 3 showing another embodiment of the present invention, and FIG. 11 is a perspective view of chips generated by the drill. 0... Center of rotation of the drill, 2... Cutting blade, 3... Cut eyebrow υ1 exit, 4... Chips, 31. To 3261/66.
71-77... Wall of chip discharge groove, 33... Protrusion, 71.0... Flat plate part of chips, 41...
・Curled part of chips. Patent applicant Toshi Hosokawa Akiyo Attorney Patent attorney Etsushi Kotani
Patent Attorney Nagaguchi 1 Masayuki Patent Attorney Takao Ito Figure 30414 (/,) Figure Figure '7'l 0

Claims (1)

[Claims] 1. A drill in which a chip discharge groove is formed in a spiral or linear shape on the shank, and a pair of cutting edges are continuously formed at the tip of the shank from the center of rotation to the outer periphery. , the front side in the rotational direction where the flat plate part of the chips formed by the cutting edge on the outer circumferential side comes into contact with the rear wall in the rotational direction of the drill, and the side edges of the chips are prevented from curling. A drill characterized in that each chip discharge groove is formed by a wall of the drill. 2. In a drill in which a chip discharge groove is formed in a spiral or linear shape on the shank, and a pair of cutting edges are continuously formed at the tip of the shank from the center of rotation to the outer periphery, each chip discharge groove is Its cross-sectional shape is approximately L-shaped, and the angle between the front wall and the rear wall in the direction of rotation of the chip discharge groove is set within the range of 70° to 120°. Drill. 3. The groove depth of the chip discharge groove mentioned above is 0.25 of the diameter of the drill.
3. The drill according to claim 1, wherein the drill is set within a range of 0.40 times. 4. The drill according to claim 1 or 2, wherein the chip discharge groove is formed with a front wall receding so that the outer circumferential side of the groove is widened forward in the rotational direction.